FIG. 7 is a perspective view of a total of a general canned linear motor common to the invention and a background art.
In FIG. 7, numeral 1 designates a moving piece, numeral 2 designates a field yoke, numeral 3 designates a permanent magnet, numeral 4 designates a field yoke support, numeral 5 designates a stator, numeral 6 designates a can, numeral 7 designates an armature winding, numeral 8 designates a refrigerant supply port, numeral 9 designates a refrigerant discharge port, numeral 10 designates a casing, numeral 20 designates a bolt for fixing the can, numeral 12 designates a cover containing a lead wire, numeral 15 designates a connector.
The moving piece 1 on one side is constituted by two of the field yokes 2 in a flat plate shape, the permanent magnets 3 attached to surfaces of the respective field yoke 2, and a total of 4 pieces of the field yoke supports 4 as a whole inserted to between the two field yokes 2, and is provided with a hollow space portion both ends of which are opened. Further, the permanent magnets 3 is constituted by arranging to align a plurality of magnets contiguously on the field yoke 2 such that polarities thereof alternately differ. Further, the moving piece 1 is supported by a linear guide comprising a slider and a guide rail, not illustrated, and using balls or a static pressure bearing guide or the like.
A canned linear motor armature constituting the stator 5 on other side is constituted by the metal-made casing 10 having a frame-like shape inside of which is hollowed, the can 6 in a plate-like shape constituting an outer shape of the casing 10 for hermetically closing the two opening portions of the casing 10, the bolt screw 20 for fixing the can 6 to the casing 10, and the 3 phase armature winding 7 arranged at a hollow space of the casing 10. Further, the armature winding 7 is unitized by molding a coil group comprising a plurality of formed coils and the background art will be specifically described later as follows. Further, the armature winding 7 is designated to differentiate as notation 72 in the background art and notation 71 in the invention.
Next, an explanation will be given of a specific structure of the canned linear motor armature in reference to FIG. 4 through FIG. 6. FIG. 4 is a side sectional view of the canned linear motor armature of the background art taken along a line A-A of FIG. 7, FIG. 5 is a side sectional view of an armature winding portion of the background art shown in FIG. 4. FIG. 6 is a side sectional view of the connector portion of the background art shown in FIG. 4.
First, the armature winding portion 72 of the background art will be explained in reference to FIG. 5. A plurality of formed coils 72c formed in a flat plate shape is soldered and fixedly arranged onto a wiring board 72a for connecting to outside of the armature as a power line or a signal line, and a surrounding thereof is covered by a resin-made frame 72b and a resin-made cover 72d. An air gap portion at a periphery of the formed coil 72c surrounded thereby is injection-molded by a mold 21 or a potting resin (not illustrated) with an object of promoting an insulation reliability of the formed coil 72c against a refrigerant.
Next, the connector of the background art will be explained in reference to FIG. 6.
A lead wire 15c led out from the wiring board 72a is soldered to a hermetic seal 15a for connecting a power line or a signal line from the wiring board 72a to outside of the armature, and a wiring portion 15d thereof is injection-molded by a high viscosity resin 15b with the object of promoting the insulation reliability of the formed coil 72c against the refrigerant.
An explanation will be given of integration of the armature using the armature winding portion 72 and the connector 15 in reference to FIG. 4.
The armature winding portion 72 is fixed to a main frame 11 by using a screw or the like, not illustrated and the connector 15 is fixed thereto by laser welding A high viscosity resin 19 is filled to an air gap portion at a periphery of a connecting portion 72e of the armature winding portion 72 and the wiring portion 15d of the connector 15 with the object of promoting the insulation reliability of the formed coil 72c against the refrigerant. Further, a first cover 13 is fixed to the wiring portion 72e of the armature winding portion 72 by using an adhering agent or the like, and the second cover 12 is fixed to the wiring portion 15d of the connector 15 by laser welding. The can 6 is fixed to a position capable of ensuring the refrigerant paths for making the refrigerant flow at a surface and a rear face of the armature winding portion 72 by interposing an O ring 16 with an object of preventing leakage of the refrigerant to outside.
By making three phase alternating currents in accordance with electric relative positions flow to the canned linear motor armature constituted in this way, a thrust is generated at the moving piece, not illustrated, by being operated with a magnetic field produced by the permanent magnet, not illustrated. At this occasion, the formed coil 72c generating heat by a copper loss is cooled by the refrigerant flowing in the refrigerant paths 17, and therefore, a temperature rise at the surface of the can 6 can be restrained (refer to, for example, Patent References 1 through 3).    Patent Reference 1: Japanese Patent No. 3592292    Patent Reference 2: JP-A-2003-224961    Patent Reference 3: JP-A-2004-312977